From the prior art it is known to make use of the pump action of the ring gear in differentials with integrated axle drive for circulating the oil volume. In this, the oil is entrained by the teeth of the ring gear in the circumferential direction and carried away with the assumed speed of the ring gear. Thus, an oil flow is formed around the rotating ring gear, but owing to the open structure of a differential this flow is turbulent, so the useful quantity of oil delivered is considerably reduced in a disadvantageous manner; from the prior art no specific way is known of optimizing the delivery function of the ring gear to maximum the flow volume.